This disclosure relates to video interpolation and in particular, to multi-channel video frame interpolation.
Video sources can have a variety of frame rates. For example, video sources related to movies produced on film can have a frame rate of approximately 24 frames per second. Video sources related to television can have frame rates of approximately 30 frames per second. However, displays may have a refresh rate of 60 Hz, 120 Hz, 240 Hz, or the like. That is, the display is updated or refreshed at a higher rate than the video source.
The frames of the lower frame rate video sources can be interpolated to create intermediate frames between the original frames of the video source. For example, motion vectors can be calculated for changes between two frames of a video source. These motion vectors can be used to create the intermediate frames by interpolating the motion of the video between the two frames. Thus, for a video source with a 24 frames per second frame rate, an additional four frames can be inserted between two of the frames to generate 120 frames per second, or a 120 Hz refresh rate.
While performing such interpolation, typically, a single frame is interpolated at a time. However, some video display techniques use multiple frames in driving a single frame of a displayed image. For example, a boost circuit for driving a liquid crystal display (LCD) can use two frames to determine an amount to overdrive the LCD to achieve a desired transition time. Since only a single frame is interpolated at a time, a previously interpolated frame must be stored in a memory to be available for combination with another, recently interpolated, frame in the boost circuit.